- Marie Tolar-Peterson
- The Conversation*
It’s a very common complaint among dieters: “Ugh, my metabolism is so slow, I’m never going to lose weight.”
When people talk about a fast or slow metabolism, what they are really trying to say is how many calories your body burns throughout the day.
The idea is that someone with a slow metabolism just won’t use the same amount of energy to do the same task as someone with a fast metabolism.
But does the rate of metabolism vary so much between one person and another?
I am a nutrition expert who focuses on the biological, environmental and socioeconomic factors that influence body composition and this question is more complicated than it seems at first glance.
But whatever the current speed of your metabolism is, there are things that will push it to run at lower or higher speeds.
The energy needs of your body
Metabolism is a biological term that refers to all the chemical reactions necessary to maintain life in an organism.
Your metabolism does three main jobs: converting food into energy; break down food into its basic components (proteins, lipids, nucleic acids and some carbohydrates); and remove nitrogen waste.
If you are distressed by the speed of your metabolism, you are probably concentrating on how much energy you get from the food you eat and how much your body uses.
The energy value of food is measured in calories.
Your caloric needs can be divided into two categories.
The basal metabolic rate is the minimum amount of calories needed for basic functions at rest.
He energy expenditure at rest is the amount of calories your body uses while resting or sleeping, which is about 60% – 65% of your total energy expenditure.
It does not take into account the calories you need for everything else you do, such as moving or spending energy on activity (25% -30%), thinking, and even digesting food (5% -10%).
Thus, your total energy expenditure combines the two: your energy expenditure at rest plus your energy expenditure in other activities.
How do we get to a number
The estimated daily caloric intake required for a 57-kilo adult woman ranges from 1,600 to 2,400 calories per day.
For a 70-pound man, daily caloric needs can range from 2,000 to 3,000 calories per day.
That is around 25-30 calories per kilogram of body weight.
In contrast, young children burn about 120 calories per pound of weight per day.
This ratio continually decreases as the child grows.
So, young children have the highest metabolism of all. This extra calorie requirement is necessary for growth.
So if two women of the same weight can have caloric needs that vary by as much as 30%, does that mean that the woman whose body consumes more calories has a faster metabolism than the woman whose body uses fewer calories?
A woman may spend more of her day physically active and therefore need more energy for example to walk to work and for her kickboxing class afterward.
Beyond those basic guidelines, there are many ways to estimate total and resting energy expenditure if you want to understand your body’s specific caloric needs.
A common and easy method is to use predictive formulas like the Mifflin-St equations. Jeer or Harris-Benedict that are based on your age, height, weight and gender to determine how much energy your body needs to be alive.
To calculate the total energy expenditure, you must also add the activity factor.
The indirect calorimetry is another way to estimate metabolic rate.
Energy expenditure is calculated by measuring the amount of oxygen used and the carbon dioxide released by the body.
Your body depends on oxygen to perform all of its metabolic functions.
For every liter of oxygen you use, you expend approximately 4.82 calories of energy from glycogen or fat.
Indirect respiratory calorimetry is typically performed in a doctor’s office, although smaller, more portable, and more affordable devices are increasingly marketed.
Metabolic rate and caloric requirements vary from person to person depending on factors such as genetics, gender, age, body composition, and amount of exercise What are you doing.
He health status and certain medical conditions they can also influence metabolism. For example, a regulator of metabolism is the thyroid gland, located in the front of the neck, just below the Adam’s apple.
The more thyroxine a person’s thyroid gland produces, the higher their basal metabolic rate.
The fever It can also affect a person’s basal metabolic rate.
For every 0.9 degree Fahrenheit (0.5 C) increase in a person’s internal body temperature, their basal metabolic rate increases by approximately 7%.
Other medical conditions that influence basal metabolic rate can include muscle wasting (atrophy), prolonged starvation, low levels of oxygen in the body (hypoxia), muscle disorders, depression, and diabetes.
Another important factor is the body composition. For example, an overweight woman with a body composition of 40% body fat and about 34 kilos of muscle mass will burn fewer calories while resting than a woman with 30% body fat and 50 kilos of muscle mass, since the Muscle tissue in the body is more metabolically active than fat tissue.
This is also the reason why the basal metabolic rate decreases with age.
As people age, they generally lose muscle mass and gain fat tissue, which equates to a decrease in basal metabolic rate of approximately 1% to 2% per decade.
If you really want to give your metabolism a boost, the easiest way to do it is to increase your muscle mass and your activity level.
By increasing muscle mass, you will also increase the basic amount of calories needed to maintain those muscles.
Instead of complaining about having a slow metabolism, you can try speeding it up to make it at least a little faster.
Marie Tolar-Peterson is a professor of Food Sciencesohn, Nutriciohny Promoción de Health from Mississippi State University, in the United States.
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Eddie is an Australian news reporter with over 9 years in the industry and has published on Forbes and tech crunch.